Artificial nail tips have been generally shown in the prior art for both cosmetic and prosthetic uses. However, prior nail tips suffer from problems of not properly conforming or fitting to natural nails. Prior nail tips suffer from the additional problem of not maintaining their structural integrity when they are forced to deform to fit a natural nail.
Prior nail tips are generally constructed in substantially rectangular shapes having a variety of lengths and widths wherein the length of a particular tip is typically several times the width. The nail tips may be cut and filed to form a particular desired shape. Prior nail tips are also provided with a particular thickness. In determining the thickness of the nail tip aesthetics, strength, and flexibility are often considered.
Nail tips are generally attached to a natural nail by overlaying and gluing a back or end portion of the nail tip onto a natural nail with the front or remaining portion of the nail tip overhanging the natural nail to form an extended nail tip. The extended nail tip which overhangs the natural nail may be cut and/or filed to a desired length and shape. Prior nail tips have been provided with an attachment or overlap end portion comprising an area of reduced thickness when compared to the other portions of the nail tip. The attachment end portion provides an area of increased flexibility which is overlaid upon and directly attached to a natural nail.
Prior nail tips also include a certain amount of curvature. Nail tips may be provided with a curvature along their length corresponding to a longitudinal curvature. The longitudinal curvature is defined by that curvature of the nail tip which exists along a line extending between the back end portion and the front end portion of the nail tip. Nail tips may be provided with a curvature along their width corresponding to an axial curvature. The axial curvature is defined by that curvature of the nail tip which exists around an axis extending the length of the nail tip (i.e. extending between the back end portion and the front end portion of the nail tip). Axial and, often times, longitudinal curvatures are provided for aesthetic and for attachment purposes.
Conventional nail tips generally incorporate an axial curvature having constant radius. However, such nail tips most often do not match the curvature of the natural nail to which the nail tip is to be attached. To attach such nail tips to a natural nail, the nail tips often must be deformed to the extent that the top of the nail tip experiences increased structural stress especially along a central portion of the top of the nail tip. In addition, the mismatch in curvatures also provides discomfort to the wearer of the nail tip and provides difficulty in attaching and fitting the nail tips by the applier. (Although the "wearer" and the "applier" are referred to here separately, the same person could be both the wearer and the applier of the nail tip.)
The wearer may experience discomfort when wearing such a nail tip due to the axial curvature of the nail tip squeezing or pinching the sides of the underlying natural nail. The applier of the nail tip may experience difficulty in attaching and fitting the nail tip to the wearer because of the uncertainty of the ability of the curvature of the nail tip to be deformed (e.g. flattened out) to properly fit the wearer's natural curvature without breaking, cracking or weakening, and because of the difficulty in filling a gap which is created between the nail tip and the underlying natural nail due to the curvature mismatch. The applier may experience additional difficulty in blending the nail tip to the natural nail to result in an aesthetically pleasing nail surface.
Nail tips of the prior art are generally formed of plastic, such as ABS plastic, tenite acetate, or nylon, which is molded into the shape of the nail tip. Such plastics generally are deformable to a certain extent. However, such plastics also maintain a memory of the curvature to which they were originally molded. A nail tip made of such plastic, therefore, exerts force to try to re-acquire its originally molded-in curvature. This force may provide the pinching effect described above. In addition, this force may make it difficult for an applier to determine the size of nail tip to be used on a wearer and to fit a nail tip to the wearer due to the difficulty in determining the extent the nail tip will deform to match the wearer's curvature. Furthermore, it is difficult for an applier to determine the extent to which the nail tip may be deformed without breaking, cracking or weakening (i.e. while maintaining its structural integrity). It is typical for prior tips to break, crack, or become weakened when deformed to a certain extent.
Prior nail tips have been shown which have attachment portions which include snap-out or cut-away areas. U.S. Pat. No. 4,805,645 to Schiff et al. shows a nail tip having a thinned attachment area with an even thinner perforated snap-out section therein. This patent asserts that the snap-out section is removable to permit increased flexibility of the attachment area and to permit a better attachment to a natural nail which has a "problem" or unusual shape or surface. The patent states that the better attachment is achieved because there is less attachment area contacting the "problem" or unusually shaped nail surface. However, snapping out the perforated area of the nail tip results in rough or uneven fragments which must be filed or cut to ensure a smooth and aesthetically pleasing nail surface. In addition, snapping out the perforated area may result in breaking or cracking the nail tip, or in weakening the structural stability of the nail tip. Furthermore, the nail tip described in this patent is shown in the figures of the patent as having a constant radius axial curvature and, therefore, suffers the problems associated with having such an axial curvature as described above (e.g. pinching).
U.S. Pat. No. 5,070,892 to Trematerra shows a nail tip having a thinned attachment area with a cut-away portion therein. The patent states that the cut-away area of this nail tip is in a symmetrical stair-step, sawtooth, or acute angle pattern which, the patent further states, permits the attachment area to be quickly and symmetrically trimmed by simply counting the number of steps or notches to be saved or removed. The patent also proclaims that the pattern of the cut-away area also provides an increased border area to be bonded to the underlying nail. The patent further reveals that the nail tip is said to be flexible due to the thinness of the attachment area and the shape of the cut-away portion. However, the jagged pattern of the cutaway section advocated by this patent does not maintain the structural stability of the nail tip when the attachment area is deformed or flexed to conform to the shape of an underlying natural nail, especially to natural nails which are flat or inconsistently shaped. In addition, the nail tip of this patent would require the application of additional overlay and bonding materials (e.g. require more blending or "feathering") to blend the jagged edges of the nail tip to the wearer's natural nail to result in an aesthetically pleasing nail surface. Furthermore, the nail tip shown and described in this patent is shown as having a constant radius axial curvature and, therefore, suffers all the problems associated with having such an axial curvature as described above (e.g. pinching).
A nail tip which has an axial curvature which is comfortable and flexible and which can be deformed while maintaining structural integrity and which is easily blended to the underlying natural nail to form an aesthetically pleasing nail surface is desirable.